1. Field of the Invention
This invention relates to surfactant mixtures which are liquid at room temperature, and more particularly, to such mixtures based on polyalkoxylated alcohols having high surfactant power comprising straight-chain and/or branched-chain ether alcohols.
2. Discussion of Related Art
The alkylphenol ethoxylates now being widely used as nonionic surfactant components show considerably better low-temperature behavior, e.g., lower pour points and low-temperature cloud points, than comparable ethoxylates based on linear fatty alcohols. Among the alkylphenol ethoxylates, the nonylphenol-10 moles ethylene oxide adduct (NP-10) in particular is distinguished by such outstanding performance properties that it may be universally used as a surfactant for detergents and cleaning preparations and also as an emulsifier for various industrial applications. In addition, this surfactant has very good degreasing properties both on metal and on fabrics. By virtue of these favorable properties, it is now by far the most significant representative in terms of quantity of the group of alkylphenol ethoxylates.
Unfortunately, these alkylpyhenol ethoxylates are attended by the disadvantage of questionable environmental compatibility, so that considerable efforts are being made at least partly to replace this technologically high-quality surfactant component by components showing better compatibility with the environment. This role could be filled in particular by alkoxylated fatty alcohols of natural and/or synthetic origin. However, their use involves the difficulty that ether alcohols of the type just mentioned only have the hydrophilicity values required in practice, i.e., cloud point for example in the range of from about 60.degree. to 65.degree. C., in those forms in which the ether alcohols are solid as such at room temperature. In practical terms, this represents a serious limitation in the attempt to replace the alkyl-phenol adducts by straight-chain and/or branched-chain fatty alcohol adducts.
An object of the present invention is to provide surfactant mixtures based on alkoxylated straight-chain and/or branched-chain alcohols, more especially corresponding fatty alcohols, which are still liquid at low temperatures, for example at temperatures down to about 10.degree. C., but which nevertheless are capable of generating high surfactant power. More particularly, an object of this invention is to provide a surfactant mixture which is at least equivalent to the nonylphenol-10 moles ethylene oxide adduct in its important technological properties without the unwanted alkylphenol structure having to be introduced into this mixture. According to this invention, it is possible to combine surfactant mixtures which are equivalent to the nonylphenol-10 moles ethylene oxide adduct in virtually every property, but which nevertheless are synthesized solely from environmentally compatible components.